Rare candy does level you up faster but in the end ...
A Pokemon who has been battling/leveling normally will always be stronger than a pure rare candy pokemon. You can google the details about it if you don't believe me.
The only reason I made this post is because apparently some people are having a hard time looking for it. Hopefully I made it a little easier for them. Note that I beat this game twice normally without cheats.
I forgot to add this pokemon:
386 - Deoxys 27C35F73 A8E9E879
If anyone knows the 5000 exp action replay code for Pokemon Ruby, post it here. Share the love yo lol
"Another important point to notice is that, while Rare Candy is an easier way to level up a Pokémon, it isn't gaining any Effort Value points, making the Pokémon somewhat weaker than a normal Pokémon would have been if was trained" - Pokemon Wiki.
If you want to use the code, use it. If you don't, then don't.
"wouldn't it be more efficient to just use level and stat modifier codes"
That's the best method lol. If people want to do that, they find the codes somewhere else then. I put the 5000 exp code so that others (who were looking for it) can use it. That's it.